Here are the description and diagnostic procedures.
DTC P0446 - EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL VALVE
1. Check Power Supply - Turn ignition switch to OFF position. Disconnect EVAP canister vent control valve harness connector. See Fig. 17. Turn ignition switch to ON position. Using a voltmeter, measure voltage between EVAP canister vent control valve harness connector terminal No. 2 (Black/White wire) and ground. If battery voltage does not exist, check for blown fuse No. 9 or fault in Black/White wire. Repair or replace as required.
2. Check Output Signal Circuit - Turn ignition switch to OFF position. Disconnect ECM harness connector. Check harness continuity between EVAP canister vent control valve harness connector terminal No. 1 and ECM harness connector terminal No. 108 (Red wire). If no continuity exists, repair open in Red wire. If continuity exists, go to next step.
3. Check Component - Check rubber tube to EVAP canister vent control valve for obstructions. Clear or clean tube as required. Check EVAP canister vent control valve and EVAP control system pressure sensor. Replace EVAP components as required. Disconnect and reconnect harness connectors in circuit and perform FINAL CHECK.
Friday, November 5th, 2010 AT 9:44 AM